A total solar eclipse is a rare event. A total solar eclipse whose path crosses right over the heart of the United States? Even rarer.

On Aug. 21, 2017, the solar system serves up a special treat. Aug. 21 is a Monday, but those Scouts and Venturers who are still on summer break should plan a big celebration. Like all the best celebrations, this one comes with its own patch.

There won’t be another total solar eclipse over the United States until 2024. After that, you must wait until 2045. In other words, when Aug. 21 arrives, make sure you’re ready. Pre-order your patches today.